Solange performs during the 2013 Pitchfork Music Festival at Union Park on July 20 in Chicago. / Barry Brecheisen, WireImage

by Ann Oldenburg, USA TODAY

by Ann Oldenburg, USA TODAY

Solange Knowles announced on her website that she is canceling her international festival dates for the summer.

"I wish I could put in words how much of a difficult decision this was," she writes, "but between moving part time to a new city, starting my son in a new school, and writing/recording my new record, I really had to make the best decision for my mental/physical health and provide some stability for my family."

Knowles, 27, just moved from Los Angeles to Brooklyn, N.Y., and her son Daniel Julez is 8 years old.

She had nine dates lined up starting on Aug. 1 in Katowice, Poland, and including Oslo, Copenhagen and London.

She adds, "I am so so sooooo sorry if I've disappointed... and really hope to make it out to those special cities soon enough."